Detergent enzymes have been marketed for more than 20 years and are now well established as normal detergent ingredients in both powder and liquid detergents all over the world. With the trend towards lower washing temperature, detergent enzyme consumption has increased during later years. Enzymes used in washing formulations comprise proteases, lipases, amylases, cellulases, as well as other enzymes, or mixtures thereof. Commercially most important are proteases.
Detergent proteases have been developed by isolation of proteases found in nature followed by testing in detergent formulations. Most detergent proteases are obtained from members of the genus Bacillus. Currently, new types of proteases enter the market, offering the possibility of giving a better cost/performance ratio at various specified conditions.
Examples of commercial protease products are ALCALASE.TM., ESPERASE.TM. and SAVINASE.TM., all supplied by Novo Nordisk A/S, Denmark. These and similar enzyme products from other commercial sources are active in detergent solutions, i.e., at pH values in the range of from 8 to 11 and in the presence of sequestering agents, surfactants and bleaching agents such as sodium borate. The ALCALASE.TM. protease is produced by strains of the species Bacillus licheniformis. The ESPERASE.TM. and SAVINASE.TM. proteases are obtained by cultivation of strains of alkalophilic Bacilli.
It would be advantageous to provide novel alkaline proteases with a unique range of substrates, pH and/or temperature optima. It would also be advantageous to isolate novel proteases or produce proteases in high yield so that the proteases could be used in vitro. It would be advantageous to determine the amino acid and/or nucleic acid sequence of these proteases in order to determine, e.g., conserved and nonconserved regions and active sites, and thus, appropriate sites for mutagenesis to improve enzyme performance and to be able to produce the proteases using recombinant DNA technology.
By determining the nucleic acid sequence of the entire protease gene, one may determine the location of promoter and signal sequences. Such sequences may be of use in the expression of heterologous polypeptides.